122 Matching Results

Search Results

open access

A study of several theoretical methods for computing the zero-lift wave drag of a family of open-nosed bodies of revolution in the Mach number range of 2.0 to 4.0

Report presenting a computation of the wave drag of a family of open-nosed bodies of revolution was computed by six approximate theories: first-order perturbation theory, second-order perturbation theory, generalized shock-expansion theory, second-order shock-expansion theory, tangent-wedge theory, and impact theory. Results regarding the pressure distributions, wave drag, and computing time for each theory is provided.

Date: September 1958

Creator: Presley, Leroy L. & Mossman, Emmet A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Multidimensional DDT modeling of energetic materials

To model the shock-induced behavior of porous or damaged energetic materials, a nonequilibrium mixture theory has been developed and incorporated into the shock physics code, CTH. The foundation for this multiphase model is based on a continuum mixture formulation given by Baer and Nunziato. This multiphase mixture model provides a thermodynamic and mathematically-consistent description of the self-accelerated combustion processes associated with deflagration-to-detonation and delayed detonatio… more

Date: July 1, 1995

Creator: Baer, M. R.; Hertel, E. S. & Bell, R. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Dynamic response of the high flux isotope reactor structure caused by nearby heavy load drop

A heavy load of 50,000 lb is assumed to drop from 10 ft above the bottom of the High Flux Isotope Reactor (HFIR) pool at the loading station. The consequences of the dynamic impact to the bottom slab of the pool and to the nearby HFIR reactor vessel are analyzed by applying the ABAQUS computer code The results show that both the BM vessel structure and its supporting legs are subjected to elastic disturbances only and, therefore, will not be damaged. The bottom slab of the pool, however, will b… more

Date: September 1, 1995

Creator: Chang, Shih-Jung

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Use of Z-Pinch Techniques for Equation of State Applications

A principal goal of the shock physics program at Sandia is to establish a capability to make accurate equation of state (EOS) measurements on the Z pulsed radiation source. The Z accelerator is a source of intense x-ray radiation, which can be used to drive ablative shocks for EOS studies. With this source, ablative multi shocks can be produced to study materials over the range of interest to both weapons and ICF physics programs. In developing the capability to diagnose these types of studies … more

Date: November 11, 1998

Creator: Asay, J. R.; Bernard, M. A.; Clark, B.; Fleming, K. J.; Hall, C. A.; Hauer, A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of a bi-directional aluminum honeycomb impact limiter design

A 120 Ton shipping cask is being developed for the on-site shipment of dry spent fuel at the Idaho National Engineering Laboratory. Impact limiters were incorporated in the cask design to limit the inertial load of the package and its contents during the hypothetical 9-meter (30-foot) drop accident required by 10CFR71. The design process included: (1) a series of static and dynamic tests to determine the crush characteristics of the bi-directional aluminum honeycomb impact limiter material, (2)… more

Date: December 1, 1995

Creator: Doman, M.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

On impact testing of subsize Charpy V-notch type specimens

The potential for using subsize specimens to determine the actual properties of reactor pressure vessel steels is receiving increasing attention for improved vessel condition monitoring that could be beneficial for light-water reactor plant-life extension. This potential is made conditional upon, on the one hand, by the possibility of cutting samples of small volume from the internal surface of the pressure vessel for determination of actual properties of the operating pressure vessel. The plan… more

Date: December 31, 1994

Creator: Mikhail, A.S. & Nanstad, R.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Impact studies of five ceramic materials and pyrex

We measured the ballistic performance of five ceramic materials (alumina, silicon carbide, boron carbide, aluminum nitride, and titanium diboride) and Pyrex, when they are backed by thick steel plates. The projectile for all tests was a right-circular cylinder of tungsten sinter-alloy W2 with length 25.4 mm and diameter 6.35 mm, fired at velocities from 1.35 to 2.65 km/s. For this threat we determined the minimum areal density of each material that is needed to keep the projectile from penetrat… more

Date: May 22, 1998

Creator: Cunningham, B. J.; Holt, A. C.; Hord, B. L.; Kusubov, A. S.; Reaugh, J. E. & Wilkins, M. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect to the High Flux Isotope Reactor by the nearby heavy load drop

In this calculation, GE-2000 cask of 25,000 lbs is assumed to drop from a height of 20-ft above the bottom of the High Flux Isotope Reactor (HFIR) pool slab with end velocity of 430 in/sec at the loading station. The consequences of the dynamic impact to the bottom slab of the pool and to the nearby HFIR reactor vessel are analyzed by applying ABAQUS computer code. The results show that both HFIR vessel structure and its supporting legs are subjected to elastic disturbances only and will not be… more

Date: June 1, 1996

Creator: Chang, S.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Analytical determination of package response to severe impact

One important part of radioactive material transport risk assessments is amount of release from packages in accidents more severe than design basis accident (US NRC 10CFR71 1995). In order to remove some of the conservatism from current risk assessments, an effort is ongoing to qualify the finite element method for predicting cask performance by comparing analytical results to test measurements of the Structural Evaluation Test Unit (SETU) cask. Comparisons of deformed shapes, strains, and acce… more

Date: December 31, 1995

Creator: Ludwigsen, J. S. & Ammerman, D. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dynamic properties of Indiana, Fort Knox and Utah test range limestones and Danby Marble over the stress range 1 to 20 GPa

The responses of the following carbonate materials to shock loading and release have been measured: Indiana limestone (18% porosity; saturated and dry), Jeffersonville/Louisville Limestones (Fort Knox limestone) (variable dolomitization, low porosity), Danby Marble (essentially pure calcite; low porosity), and a limestone from the Utah Test and Training Range (low porosity, with 22% silica). Various experimental configurations were used, some optimized to yield detailed waveform information, ot… more

Date: December 1, 1994

Creator: Furnish, M. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Parameterization of structures in HE composites using surrogate materials: A small angle neutron scattering investigation

High explosive materials used in the nuclear stockpile are composites of crystalline high explosives (HE) with binder materials, such as Estane. In such materials, there are naturally occurring density fluctuations (defects) due to cracks, internal (in the HE) and external (in the binder) voids and other artifacts of preparation. Changes in such defects due to material aging can affect the response of explosives due to shock, impact and thermal loading. Modeling efforts are attempting to provid… more

Date: July 1, 1996

Creator: Mang, J. T.; Hjelm, R. P.; Skidmore, C. B. & Howe, P. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Deflection of large near-earth objects

The Earth is periodically hit by near Earth objects (NEOs) ranging in size from dust to mountains. The small ones are a useful source of information, but those larger than about 1 km can cause global damage. The requirements for the deflection of NEOs with significant material strength are known reasonably well; however, the strength of large NEOs is not known, so those requirements may not apply. Meteor impacts on the Earth`s atmosphere give some information on strength as a function of object… more

Date: January 11, 1999

Creator: Canavan, G. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Shrapnel impact probability and diagnostic port failure analysis for LLNL`s explosives testing contained firing facility (CFF)

Lawrence Livermore National Laboratory` s (LLNL) Contained Firing Facility (CFF) is a facility to be constructed for explosives testing of up to 60 kg of explosives at LLNL` s Site 300 Explosives Test Site. The CFF will be a large, rectangular, reinforced concrete firing chamber, lined with steel for shrapnel protection. The CFF will contain several glass ports for cameras, lasers, and other diagnostic equipment to be used for data collection during planned explosives detonations. Glass is used… more

Date: May 22, 1998

Creator: Price, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

On predicting and modeling material failure under impact loading

A method for predicting and modeling material failure in solids subjected to impact loading is outlined. The method uses classical void growth models of Gurson and Tvergaard in a material point method (MPM). Because of material softening, material stability is lost. At this point, the character of the governing partial differential equations changes, and localization occurs. This localization results in mesh dependence for many problems of interest. For many problems, predicting the occurrence … more

Date: September 1998

Creator: Lewis, M. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Modeling delamination growth in composites

A method for modeling the initiation and growth of discrete delaminations in shell-like composite structures is presented. The laminate is divided into two or more sublaminates, with each sublaminate modeled with four-noded quadrilateral shell elements. A special, eight-noded hex constraint element connects opposing sublaminate shell elements. It supplies the nodal forces and moments needed to make the two opposing shell elements act as a single shell element until a prescribed failure criterio… more

Date: December 1, 1996

Creator: Reedy, E.D. Jr. & Mello, F.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

EMMA: Electromechanical Modeling in ALEGRA

To ensure high levels of deterrent capability in the 21st century, new stockpile stewardship principles are being embraced at Sandia National Laboratories. The Department of Energy Accelerated Strategic Computing Initiative (ASCI) program is providing the computational capacity and capability as well as funding the system and simulation software infrastructure necessary to provide accurate, precise and predictive modeling of important components and devices. An important class of components req… more

Date: December 31, 1996

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Calculating the shrapnel generation and subsequent damage to first wall and optics components for the National Ignition Facility

The purpose of this work is to computationally assess the threat from shrapnel generation on the National Ignition Facility (NIF) first wall, final optics, and ultimately other target chamber components. Shrapnel is defined as material.that is in a solid, liquid, or clustered-vapor phase with sufficient velocity to become a threat to exposed surfaces as a consequence of its impact. Typical NIF experiments will be of two types, low neutron yield shots in which the capsule is not cryogenically co… more

Date: August 6, 1996

Creator: Tokheim, R. E.; Seaman, L.; Cooper, T.; Lew, B.; Curran, D. R.; Sanchez, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Trends in shock initiation of heterogeneous explosives

Various data from the literature on shock initiation were examined to ascertain the relative importance of effects of porosity, particle size, and binder composition upon explosives initiation behavior. Both pure and composite explosives were examined. It was found that the main influence of porosity is manifested through changes in Hugoniot relations. The threshold for initiation was found to be insensitive to porosity, except at very low porosities. The buildup process was found to be weakly … more

Date: December 31, 1998

Creator: Howe, Philip M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Pyroshock simulation for satellite components using a tunable resonant fixture - phase 2

Aerospace components are often subjected to pyroshock events during flight and deployment, and must be qualified to this frequently severe environment. Laboratory simulation of pyroshock using a mechanically excited resonant fixture, has gained favor at Sandia for testing small (<8 inch cube) weapon components. With this method, each different shock environment required a different resonant fixture that was designed such that it`s response matched the environment. In Phase 1 (SAND92-2135) of th… more

Date: April 1, 1997

Creator: Davie, Neil T. & Bateman, Vesta I.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Structural concerns in dynamic drop loads on transfer lock mechanisms

Drop loads are usually low probability events that can generate substantial loading to the impacted structures. When the impacted structure contains slender elements, the concern about dynamic buckling must be addressed. The problem of interest here is a structure is also under significant preload, which must be taken into account in the transient analysis. For complex structures, numerical simulations are the only viable option for assessing the transient response to short duration impactive l… more

Date: July 1, 1997

Creator: Pfeiffer, P. A.; Moran, T. J. & Kulak, R. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ground motion measurements from the demolition of steel towers

Steel towers from a decommissioned heavy water plant were to be demolished. Ground motions due to the proposed felling were estimated in order to assess the structural integrity of neighboring buildings and piping systems. The extraction towers were 125 feet (38.1 m) high in two sizes: 6.5 and 11 feet (1.98 and 3.35 m) inside diameters weighing 215 X 10{sup 3} and 470 X 10{sup 3} lb (956 X 10{sup 3} and 2.1 X 10{sup 6} N). The total potential energy of the tower collapse was about 15 X 10{sup 6… more

Date: December 31, 1998

Creator: Joshi, J. R. & Lee, R. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Optical techniques for determining dynamic material properties

Miniature plates are laser-launched with a 10-Joule Nd:YAG for one-dimensional (1-D) impacts on to target materials much like gas gun experiments and explosive plane wave plate launch. By making the experiments small, flyer plates (3 mm diameter x 50 micron thick) and targets (10 mm diameter x 200 micron thick), 1-D impact experiments can be performed in a standard laser-optical laboratory with minimum confinement and collateral damage. The laser-launched plates do not require the traditional s… more

Date: December 31, 1996

Creator: Paisley, D. L. & Stahl, D. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Enhanced diffusion in shock activated Be-Al interfaces

Enhanced diffusion of aluminum in shock activated beryllium has been observed. Cylindrical samples of aluminum coated beryllium rods were axisymetrically loaded up to 40 GPa and a total residual strain of up to 6.7%. The defect microstructure produced by both the shock wave and strain enabled the transport of aluminum in beryllium to exceed its equilibrium solid state saturation. This {open_quotes}super saturated{close_quotes} aluminum, upon heating exsolves out at relatively low temperatures a… more

Date: May 1, 1997

Creator: Staudhammer, K.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nonlinear evolution of the Rayleigh-Taylor and Richtmyer-Meshkov instabilities

Scaled experiments on the nonlinear evolution of the Rayleigh- Taylor (RT) and Richtmyer-Meshkov (RM) instabilities are described under a variety, of conditions that occur in nature. At high Reynolds number, the mixing layer grows self-similarly - {alpha}{sub i}Agt{sup 2} for a constant acceleration (g), and as a power law t{sup {theta}{sub i}} for impulsive accelerations U{delta}(t) at low and high Mach numbers. The growth coefficients {alpha}{sub i} and {theta}{sub i} exponents are measured o… more

Date: November 1, 1998

Creator: Dimonte, G

Item Type: Article

Partner: UNT Libraries Government Documents Department